Pokémon HeartGold and Pokémon SoulSilver are Generation IV's remakes of the original Generation II games, Pokémon Gold and Silver. Nintendo released Pokémon HeartGold and Pokémon SoulSilver versions in Japan on September 12, 2009. The games were released on March 14, 2010 for North America and March 26, 2010 in Europe.

All 493 Pokémon can follow you, including the Shiny Pokémon, and you cannot turn off the feature. To do this, you must put the Pokémon at the first in your party (the lead Pokémon), then it will appear behind you. You may also interact with it to show how it feels right now.

All the gyms are appeared to be tougher than in the original Generation II games.

The tiles of the puzzle in Ruins of Alph can be rotated to solve the puzzle. player characters who succeeded solving the Kabuto puzzle will receive an Unown Dex from a man in the ruins.

Eusine (from Pokémon Crystal) returns, he is a character who is interested in Suicune. The player character will meet him when the player character found Suicune. His appearance also can be found at the intro video, which is a man wearing purple clothes. He will be seen whenever the character will encounter Suicune.

There is Viridian Forest in Pokémon HeartGold and SoulSilver, which the earlier versions do not have (Pokémon Gold, Silver, Crystal), though the earlier games had a forest but with no Pokémon in it.

The radio functions in the PokéGear have been altered, which the player character can manually tune the channel to listen or pressing one of the four buttons to gain immediate access to the channels available.

Some channels have to be manually tuned, and must be standing in a specific location.

Poké Flute - Must be in the Kanto region, tune manually to the upper middle section. This radio channel helps to wake up the Snorlax in Route 11.

Mysterious Transmission - Inside the chamber of Ruins of Alph, manually tune the music to the center. It produces a strange sound, which is produced by Unown. It helps to increase the chance of meeting a rare-shaped Unown.

Features

PokéWalker

The Poké Walker can connect to HeartGold and SoulSilver cartridges via infrared signals and can "hold" one Pokémon that you then carry around with you.

A Pokémon being carried around in this manner will receive experience points and closeness, as well as the player character gaining "watts", an in-game currency that can be used to find and catch wild Pokémon, search for items, and unlock new locations within the Poké Walker.

Up to three Pokémon can be captured and stored on the Pokewalker, but only one will appear on the inventory screen.

You will also be able to receive items through other Poké Walker devices using infrared.

The Poké Walker is similar to the Pokémon Pikachu 2 pedometer/virtual pet in its use of Watts as currency to trade for items.